The sun crowds the western horizon over Iraq and his eyes squint against it. Five years he has done this job, infantryman. Last year he was in Afghanistan with the 101st Airborne, searching houses and caves with his finger on the trigger and destroying Taliban communication sites in Kandahar.

Now he sleeps on the plywood floor of a canvas tent with hundreds of other well-armed young men in the desert near Iraq. They strut and huff about smoking Saddam Hussein, smoking victory cigars in his palace in Baghdad, posing for pictures under the giant golden sabers that form the city gate, then returning home to the women they hope are still waiting.

For all the precision-guided missiles plunging into Baghdad, and awesome, sterile power of the B-2 bombers coursing overhead, even the world's most lethal military can't take and hold a piece a land without putting a soldier on it.

That man will be an infantryman, and in Iraq he will depend on his discipline, his tenacity and his rifle -- just as foot soldiers who came before him did in Europe, Southeast Asia and Gettysburg.

Toney is a team leader, with a few guys under him. He threw out his shoulder in a fight and will not see combat for a couple of weeks, and he worries about those in the first wave. He wants them to worry some, too.

"I'm ready, but I'm hesitant," says Toney, 23, of Oxnard, Calif. He speaks fast, with a hint of the city. "I could die. In a month, I could be sitting in a f------ casket. A lot of guys don't understand that.

Most of the U.S. Army moves fuel and equipment, or shuffles paper, or fixes helicopters. Important jobs, and often dangerous jobs. But not infantry jobs.

Consider this: Of the 20,000 people in the 101st Airborne Division, about 4,500 are trigger-pullers.

"Close with and destroy the enemy. That's the stated mission of the infantry," said Capt. Matt Konz, 31, commanding officer of Company C, 2nd Battalion of the 327th Infantry, in the Airborne. "No one else is assigned to do that."

To join the infantry, a soldier may volunteer or score poorly enough on the aptitude test for the Army to figure he's fit for little else.

Some soldiers in other disciplines look down on them for being too stupid to do anything else, or too crazy to know better.

But ask the soldiers at Camp Pennsylvania, and they'll say the Army has two specialties: the infantry and those who support the infantry.

Supply guys bring them bullets and beans, medics patch them up, helicopter pilots haul Airborne assault troops and provide air support when they get on the ground.

The infantrymen call them POGs (rhymes with rogues): People Other than Grunts.

"The guys you see in the infantry, in my opinion, are overachievers. Glory hounds, I guess you could say," said Pfc. Jason Ragsdale, 22, of Hughes Spring, Texas, a field radio operator for the 2nd Battalion of the 327th. He has a shaved head and jug-handle ears and a twang as thick as the wad of Skoal in his lip.

"We all want to leave our marks when we leave. Guys who just want to do their three and leave, they end up being POGs."

Infantrymen have the toughest life in the Army, save for Special Forces. They train the most, exercise the longest, carry the biggest rucksacks. One of the Airborne's three infantry brigades is always on call for deployment within 36 hours, anywhere in the world.

An infantryman must master 72 tasks, more than any other Army specialty, from sighting, shooting and assembling his M-4 rifle to placing claymore mines to operating a radio. They take good care of their feet.

"Everything we do is the difference between life and death," said Sgt. Maj. Richard Montcalm, 44, of Jacksonville, the command sergeant major of the 2nd Battalion, 327th Infantry. He has been a Ranger-qualified infantryman for 24 years.

Good infantrymen are thrill-seekers, their leaders say. They play too hard, drive too fast, push the rules. Many are jocks, physically fit and full of energy.

At Camp Pennsylvania, the men play football from dawn until dusk, then wrestle at night in their tents or watch their favorite war movies -- Band of Brothers, Full Metal Jacket and We Were Soldiers -- again and again on portable DVD players.

"They're overly competitive, overly aggressive, and, if anything, I have to pull them off each other," Lt. Col. Chris Hughes, commander of the 2nd Battalion, 327th Infantry. "I've been feeding these kids raw meat since 9-11. They're ready."

For three weeks Camp Pennsylvania has been the desert home to the 327th, one of the 101st Airborne Division's three infantry brigades. It is part of the 1st Brigade Combat Team, also based at Pennsylvania, and soon is expected to drive toward Iraq.

Almost everyone in the brigade, including its commanders, sleeps on the hard floor of a tent with the mice. This week, the 327th Infantry was offered 2,000 cots, but there weren't enough for all the men. So the commanders turned them all down.

Hardness and camaraderie are part of the ethos. The 327th is called the Bastogne Brigade to honor the outnumbered men from the 101st who held the crossroads town of Bastogne, Belgium, against the Germans in the Battle of the Bulge nearly 60 years ago.

Back then, Airborne troopers wore playing cards in their helmet bands so they could identify each other by unit. The 327th drew clubs, and today there's a black club stitched to each man's helmet cover.

Ask why they chose infantry, and you'll get the same few responses: the challenge, the physical work, the weapons and the brotherhood.

"What other (job) can you do to go kick some a--, and get paid for it?" said Pfc. Joe Adams, 26, of Morrice, Mich., who mans an antitank missile. "And you can't beat the company you keep."

The infantry is all male, and the average age is 20. To turn young men into infantrymen, their leaders must harness their bravado and sense of invincibility, and apply enough discipline to keep them focused.

Hughes, of the 2nd Battalion, has spent almost 20 years in the Army, virtually all of them in the infantry. He's roguish himself, loud and unconventional, and he has firm ideas about what makes a good foot soldier.

During the Vietnam War, the 2nd Battalion of the 327th earned the nickname No Slack during seven years of fighting, and Hughes reinforces the motto constantly. The men bark "No slack!" whenever they salute him.

"I don't want a bunch of clean-cut, all-American boys. I want a bunch of overly aggressive risk-takers," Hughes said. "I expect them to push the limit. Because if they were right down the middle, they would not be good infantrymen. They would be good truck drivers, or good logisticians or good personnel management people."

* * *

By Friday morning, news reached the Bastogne Brigade that the U.S. Army's 3rd Infantry Division and the 1st Marine Expeditionary Force had moved deeper, faster into Iraq than expected.

The consensus here is that the United States and Britain will use targeted airstrikes against Baghdad to salvage what they can of roads, buildings and other infrastructure.

That means it will be up to the Airborne infantry to eject the enemy from the city, searching house to house if need be for Hussein and his lieutenants.

For the past three days, the soldiers of the 327th have worked until midnight and risen at 5, packing their trucks and rucks with ammo, food and water, and cleaning their weapons. The medics are assembling their aids kits, the Black Hawk helicopters are landing in the sand yard to pick up their M-60 door gunners.

Between duty and Scud alarms, the troops write last letters home and clean their rifles over and over. The alarms helped some realize this is no drill. Someone is trying to kill them.

A few admit worrying about what lies ahead.

Cpl. Vince Mayberry, 27, is a beefy .50-caliber machine gunner from Tennessee with a wife and two kids at home, and a third on the way. Like Sgt. Toney, he is a team leader. He is nervous.

"A little scared, too. A lot of us have not been in combat before," Mayberry said. "You're hoping that your weapon operates the right way, you're hoping you hit the target, hoping you don't get shot."

Soldiers say they're anxious to test their exhaustive training in battle. "This is the only time we get to do our job," said Sgt. Reginald Laranang, 22, of San Antonio. "A lot of guys can't wait to put the first round down-range."

Master Sgt. Ken Newsome understands. He is a large man with a smooth, bullet-shaped head who chose a life of adventure over the dead-end job at a grocery store produce deparment.

"They asked me if I wanted to be Airborne, that it was another $75 month. I said hell yeah," said Newsome, 38, of Sulfer, La.

He thought he would pull 20 years and retire, and he had had his farewell party when Sgt. Maj. Montcalm called him into his office in late January.

The Airborne was deploying to fight in Iraq. Perhaps he would like to stay.

Newsome asked the Army to defer his retirement to December, and he remained with Hughes' No Slack headquarters. Now he sleeps on the floor of a tent, cleaning his guns and preparing for his third combat mission.

"After 20 years in Army, that's all you're trained to do," Newsome said. "To watch them get shipped off, and not know what the outcome would be, just to watch them leave on the news, that would eat my heart out.

"Especially if one of them died. And that's pretty much the way it is with most infantry."